Writing instrument



FIG. 1 is a bottom, left side, and rear perspective view of a writing instrument showing our new design;

FIG. 2 is a front, left side, and top perspective view thereof;

FIG. 3 is a left side elevation view thereof;

FIG. 4 is a right side elevation view thereof;

FIG. 5 is a rear elevation view thereof;

FIG. 6 is a front elevation view thereof;

FIG. 7 is a bottom view; and,

FIG. 8 is a top view thereof. 

The ornamental design for a writing instrument, as shown and described. 